JSFiddle - React, Tailwind, and code Playground

HTML

<div id="mainDiv">
    <div id="first">div1 with little content</div>
    <div id="second">adsdweeqwrqwrtqwrqwtqwtqwtqwtqtqwtqwrqwrqwrqtqwetwetwetwtwrteryyrtyeryeryeryeryeseseqwewqeqwrqwrrsarasrararqwrwrqwrqwrqwrqwrr</div>
</div>

CSS

#mainDiv { 
    border: 1px solid black;
    height: 670px;
}

#mainDiv div {
    position:relative;
    border: 1px solid red;
    float: left;
}
#first {
    top: 170px;
}
#second { 
    height: 400px;
    top: 65px;
}